Have 1984 F150 with 302 and 3 speed auto 4X4 with 122K miles. Does run rich and it has been at 8000 foot elevation for years. Timing is advanced 9 degrees to 19 for the high altitude. Trying to find a 2150 carb with aneroid for the altitude compensation ability with no success.

Testing was done in CA at 1000 feet.

Numbers from the smog test today:

CO%

Max .087 Gross Polluter 2.17 Measured (Actual) 4.97 at 15 mph
Max .077 Gross Polluter 2.40 Measured (Actual) 4.88 at 25 mph

Nothing was done prior to the test.

HC%
Max 131 Gross Polluter 320 Measured (Actual) 291 at 15 mph
Max 103 Gross Polluter 270 Measured (Actual) 317 at 25 mph

Will change the oil, air filter and spark plugs and lower the timing
back to stock 10 degrees for retesting.

Any other suggestions? It has a Motorcraft 2150 2 bbl carb. Truck
starts very well, idles smooth and runs well...burns a little oil. Need to
be able to register it in CA from ID. Will pull and rebuild the engine
if I can get ir re-registered.

 

While I am new to Ford trucks I have been living in CA and dealing with the SMOG regulations for some time and I can say you are on the right track. It is also worth checking the oxygen sensors to make sure that those are not fowled up. If those get too full of deposits then your vehicle can run a little rich. It might be worth popping them out for a visual inspection.

Good luck!